# Law of Sines/Cosines

• Dec 2nd 2007, 07:12 PM
xsolutionx
Law of Sines/Cosines
1. For each of the triangles below, find all the missing sides and angles for each problem. Here is a photo of the angles that need to be found.
http://i3.photobucket.com/albums/y76...assignment.jpg

2. Graph the following sine waves and list the amplitude, the period, and the phase shift.
A) Y = 4sin(2x)

B) Y = 2sin( ½ x + 90)

thanks a ton in advance guys! this stuff has really been bothering me and i've searched everywhere for solutions or help. i hope you guys can!
• Dec 2nd 2007, 07:23 PM
Jhevon
Quote:

Originally Posted by xsolutionx
1. For each of the triangles below, find all the missing sides and angles for each problem. Here is a photo of the angles that need to be found.
http://i3.photobucket.com/albums/y76...assignment.jpg

2. Graph the following sine waves and list the amplitude, the period, and the phase shift.
A) Y = 4sin(2x)

B) Y = 2sin( ½ x + 90)

thanks a ton in advance guys! this stuff has really been bothering me and i've searched everywhere for solutions or help. i hope you guys can!

does this help?

note that you should think of $y = 2 \sin \left( \frac 12x + 90 \right)$ as $y = 2 \sin \frac 12 (x + 180)$
• Dec 2nd 2007, 07:26 PM
xsolutionx
hmm i don't really understand 100% so for my missing angles problems use that formula you just posted? the sine wave graph looks pretty intense but hopefully i can get it working.
• Dec 2nd 2007, 08:51 PM
Jhevon
Quote:

Originally Posted by xsolutionx
hmm i don't really understand 100% so for my missing angles problems use that formula you just posted? the sine wave graph looks pretty intense but hopefully i can get it working.

don't let the diagram scare you. for (A), the amplitude is 4, the period is pi, there is no phase shift or vertical shift, and it would be best to graph it between [0,pi]

for (B), the amplitude is 2, the period is 4pi, the phase shift is -180 degrees, there is no vertical shift, and you should graph it between [-pi, 3pi] ...radians